Tracking of people in crowded scenes is challenging because pecause
people occlude each other when they walk around. The latest revision
of our person tracker uses adaptive appearance models that explicitly
account for the probability that a person may be partially occluded.
All potentially occluding targets are tracked jointly, and the most
likely visibility order is estimated (so we know the probability that
person A is occluding person B). Target size adaptation is performed
using calibration information about the camera, and the reported
target positions are in real-world coordinates.

This movie shows real-time tracking of people under occlusion. Note that people are
succesfully tracked even when they walk in front of each other, or when they walk very
close to each other and then retreat. (6.5MB)

This movie show real-time tracking of a person in two cameras. The top figure is a top-view
showing the estimated world location of the person (marked by X). (2.7MB)

This work is supported by grants from the National Science Foundation, the Minnesota Department of Transportation, the University of Minnesota ITS Institute, and the Department of Homeland Security.
Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.